Fig. 1. Changes in plasma glucose (A), insulin (B), and glucagon (C), insulin-to-glucose ratio (D), glucagon-to-insulin ratio (E) and percent change of glucagon-to-insulin ratio (F) response during 75-g oral glucose tolerance test (OGTT) before and after sitagliptin treatment. Values are presented as mean±standard error. (Glucagon/insulin) %change=100×[(glucagon/insulin at 30, 60, 90, or 120-minute)-(glucagon/insulin at 0 minute)]/(glucagon/insulin at 0 minute). Open circles and dashed lines indicate measures before sitagliptin treatment; closed squares and solid lines indicate measures after sitagliptin treatment. "P for trend" indicates the comparison of time course curves during OGTT, analyzed by repeated measures analysis of variance. ^aP<0.05 at the 0, 30, 60, 90, or 120-minute time points using Wilcoxon signed rank test for paired values.